Claws Mail Alternatives

Thunderbird is a free email application that's easy to set up and customize - and it's loaded with great features!

Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.

Mailspring is a mail client for Mac, Windows and Linux.

Apps/Evolution - GNOME Wiki!

eM Client is a fully-featured email client for Windows and macOS with a clean and easy-to-use interface. eM Client also offers features for calendars, tasks, contacts, notes, and chat.

freemium

Mailbird is the best email client for Windows 7, 8 and 10

The Power Email App for busy professionals, like you.

Geary is an email application built for GNOME 3.

Sylpheed is a simple, lightweight but featureful, and easy-to-use e-mail client (mailer, MUA).

Secure email with absolutely no compromises. Get your free encrypted email account today.

freemium €5.0 / Monthly (user - 5 GB)

Add forums and commenting to your site. Unlimited posts, users and traffic, for free. Embeddable, styleable and scriptable.

Starting with version 0.9.8, mu provides an emacs-based e-mail client which uses mu as its back-end: mu4e.

K-9 is an opensource email client making it easy to chew through large volumes of email.